摘要
本文记述了山东临朐山旺组(中新世中期)出产的两件鸟类化石。一件主要保存了前、后肢,其构造与此前这里出产的秧鸡科(Rallidae)的秀丽杨氏鸟(Youngornis gracilis Yeh,1981)的近似,但个体明显比它大,且股骨的特征也不同,因而另订一新种,名齐鲁杨氏鸟(Youngornis qiluensis,sp.nov.)。另一件标本只保存了头骨和嘴喙,其构造如鸦类者,因材料不足,只鉴定为鸦科。(corvidae)属种未定。
Two fossil birds collected from Shanwang Formation, Middle Miocene (about fifteen million years ago), of Linqu, Shandong are here described. One of them was unearthed in 1982 (Linqu Palcon. Mus. No. 82001), and includes chiefly the prints of anterior and posterior legs; the second one was obtained in 1984 (No. 840170), and includes only a broken skull and its bill, both specimens are represented by a positive and a negative sides. These two fossil birds, though found from same locality and formation, belong obviously to different group in view of their characters. Ⅰ. Order Gruiformes Family Raillidae
Genus Youngornis Yeh, 1981 Youngornis qiluensis, sp. nov. (Fig. l, P1. Ⅰ)
Type A fossil bird including chiefly the prints of anterior and posterior legs, scapula, and fragmental skull.
Locality and Horizon Linqu, Shandong; Shanwang Formation, Middle Miocene.
Diagnosis A medium size rail, bones of its anterior and posterior legs long and slender. Length of humerus slightly longer than that of ulna, tarso-metatarsus shorter than tibia and than its middle toe with claw. Four toes, anisodactylous foot in form, hind one (hallux) shorter and higher than others. Phalanges and claws of all toes long and slender. Femur relatively short, and with a somewhat flat femoral head.
Remarks. In view of the long and slender limbs, especially the humerus longer than ulna, the tarso-metatarsus shorter than tibia, and the slender toes, the present specimen is really similar to Youngornis gracilis Yeh 1981 from Linqu, Shanwang Formation too, but it differs still from latter one by its obviously large size, and by its shorter femur with a somewhat flat femoral head. It therefore seems reasonable to consider our specimen a new species of Youngornis, and named as Y. qiluensis, sp. nov. The specific name is formed by two ancient names for Shandong Province.
According to the records, both living and fossil rails are numerous and enipy a wide geographical and stratigraphical distribution. In China, though 18 living species have been known, fossils of them are still rare except the fragments from Quaternary of Choukoutien belonging to living species. The earliest record of this animal group known in our country is the occurrence of a Late Eocene broken femur from Inner Mongolia named as Telecrex grangeri. It is said that the femoral head of this species is somewhat flat too. So far, Youngornis gracilis and Y. qiluensis, sp. nov., from Shandong represent the well fossil rails known in China.
Ⅱ . Order Passeriformes Family Corvidae
Gen. et sp. indet.
(P1. Ⅰ)
The second specimen here described is a bird skull connected with its bill. Most bones of the skull have been damaged, only the outline of it can be observed. Skull rather large, laterally preserved, attains a length in 47 mm. and a height at its frontal in 31.5mm.. Maxilla and premaxilla well preserved, stout in form, anterior end of latter one neither thinned down nor curved as a hook. Bill 42.5 in length, roughly as long as that of its skull, this is one of main diagnoses of crows. Lower jaw straight, connected still with its upper jaw, bsars a length of 74 mm., but the structure of its bones are obscure.
Bscause of the incomplete specimen, and the skull and its bill offer us only a litter characters that we can not make a detail determination for it. In view of the outline of the skull, the large size of it, the long and stout bill, and the roughly equal length of skull and bill, it seems that we faced a fossil crow which is sparely known, so far, in China.
关键词
鸟类化石
中新世中期
形态学
Linqu, Shandong, Fossil birds, Middle Miocene, Morphology and classification.
